I have a BLE beacon and I was wondering if adding a capacitor in parallel with the coin cell battery would help with the battery life by smoothing out the peaks. The scenario shown in the chart is the BLE advertising event (every 1s). So I first added a 10uF then also a 100uF capacitor in parallel and took a trace of the power profile. The two series shown is with a 10uF capacitor (orange line) and the other series with both 10uF+100uF capacitors (blue line). Looking at the charts, I have two questions:
For the 100uF series, why is there a large spike at the start of the advertising event ? I expected the larger capacitor to help smooth out the initial peak of the advertising event not make it worse. (there's a bit of CPU work before the main spike which is smoothed out but that should not deplete the capacitor). Instead, it looks like its charging at the same time and I suspect there needs to be some way to limit the draw of the capacitor. I tried adding in various resistors but that just converges to not having a capacitor in the first place.
It does not look like adding in the 100uF is helping at all, are there ways to make it help and not hurt or is it better to not have it ?
Thanks for the replies. Turns out to be buggy UI software. I reran the tests with different s/w and got results more inline with what you would expect.